A study of the aftereffect of the magnetic permeability in Co-rich amorphous ferromagnetic alloys

Abstract

Room-temperature measurements of saturation magnetization, saturation magnetostriction, and aftereffect of the magnetic permeability have been performed on a set of Co-based amorphous ferromagnetic alloys with magnetostriction values in the range −4×10−6 ≲λs≲+1×10−6. The theoretical relation between aftereffect and λs has been verified to hold also in Co-rich amorphous alloys. The fraction of atoms participating in the ordering processes giving rise to the aftereffect is calculated to be of the order 10−4. The aftereffect is shown to be related, even in these alloys, to a damping of 180° Bloch walls, whose thickness increases with decreasing λs. The influence of the alloy’s stability on the permeability aftereffect is discussed in detail.